[LaBelleShell]

Having awful issues with what I think are called Sciarid Flies. I have successfully grown from seed lots of coriandar and basil. But noticed the occasional blackfly around them (these generally appear whenever I bring herb plants from tesco into my apartment) and usually these plants die within a few days of purchase. Since moving these seeds from the propagator to pots they have all died. I can see movement in the soil whenever if go near these pots. There are small black flies in apartment now too.

What i have read online about these are: They lay their eggs in the wet soil and the larvae in the soil feed on the new roots of small herbs and can effectivly kill them altogether. Which has now occured with all my basil and coriandar which I grew from seed. The adult turns into a fly (I now have quite a few in my apartment) and the eggs can lie dormant in the soil. I'm desperately trying to find out how to get rid of it but still have the herbs edible.

Sticky Yellow traps are apparently good for killing adults flies but not sure how to get rid of the larvae yet. Changing the compost will fix temporarily but if there are still adult flies they'll just lay new eggs in the new compost. I've read that Bifenthrin can kill them but this might just be available for larger crop farmers.

Just out of interest the herbs I started growing in a non peat soil are flourishing and have not been attacked. Apparently these pests only like compost/peat soils.

Any help would be appreciated.